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This paper describes the life-saving mechanism in accidents while a force wheeler drives on the lane. Safety systems in automobile have slowly gained attention over the past decade. Airbags are among the greatest significant products for automotive security, as they have been shown to upsurge passenger safety in a variety of ways. An airbag is an automobile safety device used to save both drivers and passenger’s lives during a collision. The airbag modules contains of an initiator inflator, a pad of textiles, and frame. An airbag's function is to shield occupants during a crash and protect their bodies when they hit interior objects like steering or window, etc. The use of the airbag system reduces the number of injuries by decreasing the force exerted at any point on the body by the steering wheel, Windows and dashboard. Many researches are going to improve the airbag's features. However, the effectiveness of any safety equipment depends on its proper implementation and on certain guidelines to be followed.

Transportation of a large amount of goods and materials to the lunar surface will be an urgent need with the increasing intensive exploration of the moon. The airbag cushioning system is the most prospective one due to its low cost, simple structure, adjustable performance, and well stability, when compared to other types like the soft-landing mechanism and sky crane. The special lunar environment of the thin atmosphere and low gravity calls for new types of the combined airbag. Thus, a new combined airbag structure that can avoid generating a lot of dust during venting was proposed to fit the lunar environment. By proposing an improved deformation assumption of the airbag based on large deformation, as well as considering gas exchange between main and secondary airbags, a novel combined airbag analytical model was put forward. The inflation and cushioning process were calculated and validated through simulation analysis and ground test. The analytical, numerical, and experimental results were in good agreement. Using the analytical model, the lunar landing cushioning process of the combined airbag with different layouts was analyzed, and the optimal layout was determined. Furthermore, parameter effects on the cushioning performance were studied. The results show that: main airbag initial pressure, venting threshold pressure, vent orifice diameter, and secondary airbag volume have a great impact on cushioning performance, while inflation gas temperature has little impact. Notably, the influence law of these parameters is not monotonous.

Vehicle restraint systems play an irreplaceable role to limit passenger injuries when an accident occurs, in which, the 3D acceleration sensor (AS) is an essential component to detect the collision position and force. However, there are some defects for commercial sensors such as passive sensing, low sensitivity and high manufacturing cost. Here, we report a lightweight, high-sensitivity, low-cost and self-powered 3D AS based on a liquid–metal triboelectric nanogenerator (LM-TENG). In view of the coded strategy of the electrodes, the 3D AS retains the smallest size, lowest weight and highest integration compared to the currently reported self-powered AS. The fabricated sensor possesses wide detection range from 0 to 100 m/s2 in the horizontal direction and 0 to 50 m/s2 in the vertical direction at a sensitivity of 800 mV/g. The open-circuit voltage shows a negligible decrease after continuously operating for 100,000 times, showing excellent stability and durability. Furthermore, the 3D AS is demonstrated as a part of the airbag system to spot the collision position and force of the car simultaneously. This work will further promote the commercialization of TENG-based sensor and exhibits a prospective application in the vehicle restraint system.

In an automobile vehicle, azide based conventional fuels are used for airbag inflation. The exposure of sodium azide leads to several health issues such as hypotension, indigestion, breathing difficulties, eyes burning, itching, drowsiness etc. This made the focus shifted towards finding out a non azide fuel suitable for an airbag inflation. This paper discusses about the selection and procedural implementation of a suitable non azide fuel for an airbag gas generants by forming a ranking matrix. Ranking matrix were formed based on the economic and hazardous parameters such as toxicity, instability and inflammability factors. The detailed literature survey on the different non-azide fuels available and performance evaluation techniques showed that Differential scanning calorimetry (DSC), Thermogravimetry (TG), Accelerating Rate Calorimetry (ARC) were used for evaluating the thermal parameters such as peak pressure, heat of formation, burning rate, pressure rate and decomposition temperature. The review was found useful to select various modelling and numerical techniques proposed by researchers for calculating the kinetic parameters such as activation energy, pre-exponential factor and reaction rate. These performance parameters of the conventional azide fuels can be kept as a bench mark while evaluating the non azide fuel. This review aids the researchers to choose a non azide fuel based on ranking matrix and to carry out performance analysis for a possible substitution of conventional azide based airbag fuels.

The contribution deals with the basic principles of operation of EDR technology and the further process of obtaining and using data for the reconstruction of an accident. One of the many devices that leave a digital evidence is the EDR memory module, which is contained in the airbag control unit of a car and which can record and store data from the accident. The CDR system enables to download and decode the stored data from the airbag control module, that experts can use among others for the technical analysis of an accident and objectively reconstruct it. The future of the analysis of traffic accidents will lie in use of the CDR system and the correct evaluation of the technical data obtained from the memory of the airbag unit. Legislative and technical preparations, which are currently taking place in Europe, aim to establish clear rules and requirements for OEM companies to implement Event Data Recorder (EDR) all over. It shows what data should be stored in airbag unit, how long is the section and what frequency must be used for data acquisition. The aim of these preparations is to establish clear rules for passenger car manufacturers (category M1 and all vehicles complying with the requirements), which should enter into force in 2022.

In this study, thermal characterisation of stoichiometric azodicarbonamide/potassium periodate (C2H4O2N4/KIO4) fuel/oxidizer mixtures were systematically carried out for potential application as non azide non-toxic airbag gas generants. The onset temperature of the mixture was found to be 190 °C. The thermo-kinetic studies of the mixture and pure azodicarbonamide compositions at different heating rates were also carried out using Ozawa and Kissinger method and the Arrhenius parameters were computed. The activation energy of the C2H4O2N4/KIO4 mixture by Ozawa method was found to be 81.5 kJ mol−1 and 78.9 kJ mol−1 by Kissinger method. It was found that the activation energy of the pure azodicarbonamide was higher compared to the mixture. Ballistic tank tests to obtain the pressure Vs time plots were also done and the mixture gave time response of 45.2 ms and 55.54 ms to peak pressure. The experimental results have shown that C2H4O2N4/KIO4 mixture can be used as a replacement to existing azide based airbag gas generant compositions. Thus, the paper attempts to thermally characterize a non-toxic C2H4O2N4/KIO4 airbag gas generant mixture which can replace toxic azide based airbag gas generants and thereby facilitate safer driving.

The primary purpose of an avalanche airbag is to prevent burial during an avalanche. Approximately twenty percent of avalanche victims deploying airbags become critically buried, however. One avalanche airbag actively deflates three minutes after deployment, potentially creating an air pocket. Our objective was to evaluate this air pocket and its potential to prevent asphyxiation.Twelve participants were fitted with an airbag and placed prone on the snow. Participants deployed the airbag and were buried in 1.5 m of snow for 60 min with vital signs including oxygen saturation (SpO2) and end-tidal CO2 (ETCO2) measured every minute. Participants completed a post-burial survey to determine head movement within the air pocket.Eleven of the 12 participants (92%) completed 60 min of burial. Preburial baseline SpO2 measurements did not change significantly over burial time (P 0.05). Preburial baseline ETCO2 measurements increased over the burial time (P 0.02); only one ETCO2 value was outside of the normal ETCO2 range (35-45 mmHg). Participants reported they could move their head forward 11.2 cm (SD 4.8 cm) and backward 6.6 cm (SD 5.1 cm) with the majority of participants stated that they had enough head movement to separate the oral cavity from opposing snow if necessary. Visual examination during extrication revealed a well-defined air pocket in all burials.The avalanche airbag under study creates an air pocket that appears to delay asphyxia, which could allow extra time for rescue and improve overall survival of avalanche victims.

Activation time for activating the occupant restraint systems (airbag and seatbelt) is very critical for an optimal safety action. A crash-pulse is the deceleration of the vehicle measured during in a crash. The shape, slope, maximum deceleration and duration of the crash-pulse provides significant information over the nature of occupant motions during in-crash phase and hence the crash severity. The above parameters of the crash-pulse not only depend on the mass and impact velocity but also on the crash configuration (position of impact, overlap, relative approach angle etc.). This study focuses on analysis and characterization of crash-pulses in head-on collision cases with varying overlap configurations. The paper describes causes for occupant injuries during a crash, crash-pulse and its important physical parameters, and different methodologies used to analyse the crash-pulse. Finite element simulation method is used to study the crash-pulses from different crash configurations. A new severity index that has direct influence on the occupant kinematics is defined. The results show that the steep decrease of crash-pulse for small overlap configurations (less than 25 percent of vehicle width) lags by 20 to 25 milliseconds as compared to configurations with large overlaps. The shape of the crash-pulse also changes for crash scenarios with different overlap configurations. The results, discussion and conclusion sections of this paper provide a summary of crash behaviour of varying overlap crash scenarios and insights that can be used for deployment of restraint systems.

Air gun shock systems are commonly used as alternative explosion energy sources for underwater explosion (UNDEX) shock tests owing to their low cost and environmental impact. The airbag inflator of automotive airbag systems is also very useful to generate extremely rapid underwater gas release in lab-scale tests. To overcome the restrictions on the very small computational time step owing to the very fine fluid mesh around the nozzle hole in the explicit integration algorithm, and also the absence of a commercial solver and software for gas UNDEX of airbag inflator, an idealized airbag inflator and fluid mesh modeling technique was developed using nozzle holes of relatively large size and several small TNT charges instead of gas inside the airbag inflator. The objective of this study is to validate the results of an UNDEX response analysis of one and two idealized airbag inflators by comparison with the results of shock tests in a small water tank. This comparison was performed using the multi-material Arbitrary Lagrangian-Eulerian formulation and fluid-structure interaction algorithm. The number, size, vertical distance from the nozzle outlet, detonation velocity, and lighting times of small TNT charges were determined. Through mesh size convergence tests, the UNDEX response analysis and idealized airbag inflator modeling were validated.

We present a novel high-speed sensor for simultaneously measuring the three-dimensional (3D) shape and the surface temperature of fast moving objects. The 3D topography is obtained by a structured light sensor based on GOBO projection of aperiodic sinusoidal patterns in the visible range of light. At the same time, a high-speed long-wave infrared camera records the temperature distribution on the object surface. We show first promising 3D thermography measurement results of an inflating airbag, a basketball player, and the crushing of a metal tube conducted at a 3D frame rate of 1 kHz.

Background Many studies have investigated the issue of facial injuries caused by car accidents, but only a few have addressed the technical and clinical aspects of such accidents and injuries in depth. The aim of this study was to identify risk factors and protective elements for facial injuries in car accidents. Methods We analysed the technical and clinical data of patients with facial injuries caused by car accidents over a 16-year period (2000–2016) and investigated the following factors: sitting position, sex, age, accident time, use of a seatbelt, deployment of the front airbag, direction of impact, speed at the time of collision, and occurrence and location of facial injuries. Results Of the 1291 patients involved in car accidents who were included in our study, 291 (22.5%) had suffered facial injuries. We found a significant association between occurrence of facial injuries and sex, speed at the time of collision, impact from the back, seatbelt usage, and deployment of the front airbag. In accidents occurring at speeds over 40 km/h, automobile security measures had no significant influence on the occurrence of facial injuries in drivers and front-seat passengers. In accidents occurring at speeds between 0 and 20 km/h, seatbelt usage (without airbag deployment) solely showed a significant protective influence against the occurrence of facial injuries (odd ratio [OR], 0.130; confidence interval [CI], 0.038–0.451). In contrast, patients who were in accidents at speeds between 21 and 40 km/h suffered significantly fewer facial injuries when wearing a seatbelt with the front airbag being deployed (OR, 0.245; CI, 0.091–0.665) or undeployed (OR, 0.216; CI, 0.084–0.561). Conclusion Male sex and a high speed at the time of collision are significant risk factors for the occurrence of facial injuries. The security measurements evaluated in this study only exerted a protective influence at low speeds (below 40 km/h). This indicates a possible weakness of these security systems with regard to preventing facial injuries. Engineers could benefit from these findings and improve the efficiency of existing security measures and eventually help decrease the incidence of facial injuries.

With the exploration missions to Mars gradually turning from detection of the surroundings to landing patrol, an airbag cushion system has become a new research area. A large number of researchers have simulated the airbag landing buffering process through numerical calculation methods, and applied the simulation results to optimise the airbag system parameters. According to a summary of previous studies, the researchers have all used a continuous geometry to simulate an impacted surface. Such a model cannot truly reflect the discrete morphological features of the Martian surface, however, and cannot predict the actual airbag cushion characteristics of the Martian subsurface. Based on this problem, this work proposes the use of discrete elements to study the cushioning characteristics of an airbag. This method has certain advantages in simulating the discrete surface of Mars and the dynamic characteristics of discrete surfaces after an impact. At the same time, to simulate the cushioning process of an airbag on the discrete ground, it is necessary to focus on a method of modelling the airbag based on the discrete element theory. We establish a three-dimensional particle-spring equivalent model of an inflatable airbag microelement based on the discrete element idea, and the model parameters are matched based on theory and a simulation. Finally, the discrete element simulation model of a spherical inflatable airbag is established using the discrete element simulation software EDEM, and the reliability of the model is verified by comparing the experimental and simulation values. Based on a theoretical derivation, the physical quantities that affect the airbag acceleration are obtained; these physical quantities are used as variables to perform a multi-condition simulation analysis, and the preliminary variation law between the acceleration and physical quantities is obtained. Further, a multi-ball model for a multi-state simulation analysis is described, along with the simulation results used to predict the cushioning characteristics of the airbag landing in the Martian environment.

PTWs usually are cheaper than cars, they have lower energy consumption and fewer polluting emissions than larger vehicles. So, over the last decade there has been a significant increase of PTW circulating park. When riders are involved in an accident, legs are the most frequently injured part of the body. The aim of this paper is to assess the performance of a preliminary concept of inflatable leg protector mounted on a motorcycle. Five impact configurations were simulated in a finite element virtual environment, with the car impacting laterally on the motorcycle. Both stationary and moving motorcycle crashes were performed, while the car speed was 50km/h in every configuration. The rider was represented by a Hybrid III dummy model. Since the model was not validated for side impacts, a comparative analysis was performed. A set of safety parameters was used to assess the performance of the device. Their reduction was obtained in specific impact conditions, although mixed with load increases. Despite a widespread parameter reduction was not achieved, the results demonstrated the potential of the proposed device for lower limb protection, and they allowed the identification of the most severe conditions to be used in future development

We present a case of a fatal motor vehicle collision of a 22-year-old car driver, who died at the scene after losing control of his car, and subsequently collided with a tree by the roadside. The subsequent autopsy revealed penetrating injuries on the neck, severing the larynx, carotid artery, jugular vein and fracturing the cervical vertebrae. Internal examination showed the offending material to be a semi-cylindrical metal fragment, which had lodged within the paravertebral muscle. Examination of the car with the authorities found that the metal fragment originated from a defective airbag booster cannister, which shattered upon deployment.

Current metal recycling techniques for end-of-life vehicles (ELV) are based on mechanical treatments to mainly recover steel, aluminum, copper, and zinc alloys. Such techniques facilitate compliance with the ELV European Directive (2000/53/EC) target of achieving recyclability quotes of up to 85%. However, a vehicle can use more than 60 metals, some of them considered critical by international institutions, which end up downcycled as part of alloys or ultimately in landfills. This paper undertakes an assessment of the downcycling degree of minor metals in conventional vehicles using a SEAT Leon III model as a case study. Downcycling is assessed from a thermodynamic point of view using thermodynamic rarity, an indicator that is used as a weighting factor for the metals used in the car. The thermodynamic rarity of metals is a function of the quality of the minerals from which they stem, considering their relative abundance in Nature and the energy intensity required to extract and process them. The results demonstrated that, even if the quantity of downcycled metals only represents 4.5% of the total metal weight of the vehicle, in rarity terms, this figure increases to approximately 27%. This indicates that an important portion of high-quality metals becomes functionally lost. The most downcycled vehicle subsystems are in order: (1) accessories, (2) electrical and electronic equipment, (3) exhaust system, and (4) engine. Further, the most downcycled parts are: speed sensor, control unit, antenna amplifier, airbag circuit, temperature and rain sensors, front pipe, particle filter, and turbo parts.

Background Literature predating routine availability of airbags reported an association between seatbelt signs and internal injuries. We measured this association among patients involved in motor vehicle crashes (MVCs) with airbag deployment. Methods We conducted a retrospective cohort study by chart review of all MVC patients presenting to our Emergency Department (ED) during 1 January 2008–30 September 2015. We included all adult MVC patients in the driver or front passenger seats with both shoulder and lap seatbelts and airbag deployment. Two trained chart abstractors recorded data regarding restraints and airbag deployment. We obtained all other data via electronic medical record abstraction including demographics, injuries, and survival. We compared the prevalence of cervicothoracic and intra-abdominopelvic injuries between patients with a documented seatbelt sign versus no seatbelt sign using a logistic regression model. Results Of 1379 MVC patients, 350 met inclusion criteria. Of these, 138 (39.4%) had a seatbelt sign. The prevalence of cervicothoracic injury was higher among subjects with a documented seatbelt sign (54.3% versus 42.9%, p = 0.036) Seatbelt sign predicted cervicothoracic injury with a positive likelihood ratio of 1.3 (95% CI 1.0–1.7) and negative likelihood ratio of 0.8 (95% CI 0.7–1.0). The odds ratio of cervicothoracic injury among patients with a seatbelt sign versus no seatbelt sign was 1.58 (95% confidence interval 1.02–2.46) in the logistic regression model. There was no association between seatbelt sign and intra-abdominopelvic injury (p = 0.418). Conclusions In the setting of airbag deployment, there is an association between seatbelt sign and cervicothoracic injury but not intra-abdominopelvic injury.

To execute Mars surface exploration missions, spacecraft need to overcome the difficulties of the Mars entry, descent, and landing (EDL) sequences. Previous landing missions overcame these challenges with complicated systems that could only be executed by organizations with mature technology and abundant financial resources. In this paper, we propose a novel integral design methodology for a small, simple Mars lander that is achievable even by organizations with limited technology and resources such as universities or emerging countries. We aim to design a lander (including its interplanetary cruise stage) whose size and mass are under 1 m3 and 150 kg, respectively. We adopted only two components for Mars EDL process: a “membrane aeroshell” for the Mars atmospheric entry and descent sequence and one additional mechanism for the landing sequence. The landing mechanism was selected from the following three candidates: (1) solid thrusters, (2) aluminum foam, and (3) a vented airbag. We present a reasonable design process, visualize dependencies among parameters, summarize sizing methods for each component, and propose the way to integrate these components into one system. To demonstrate the effectiveness, we applied this methodology to the actual Mars EDL mission led by the National Institute of Information and Communications Technology (NICT) and the University of Tokyo. As a result, an 80 kg class Mars lander with a 1.75 m radius membrane aeroshell and a vented airbag was designed, and the maximum landing shock that the lander will receive was 115 G.

The research reported in this study investigates the use of machine learning algorithms that receive real time sensory input from three-axis accelerometers and gyroscopes strategically placed on a human body to detect a fall-in-progress early enough and prior to the impact to facilitate inflation of a body airbag. A publicly available dataset that entails 30+ subjects and 4+ fall types including fall forward, backward, left and right was employed in the study. A set of 12 attributes were defined and provided as inputs to machine learning classifiers. Two machine learning classifiers were trained and tested with the dataset through three-fold cross validation to determine the feasibility of the proposed approach. Specifically, Random Forest and Support Vector Machine classification algorithms were employed through ensemble-in-time and their performances were profiled. Both classifiers offered promising performances as they were able to detect entry into the so-called the “free fall phase” for most combinations of the test subjects and fall types considered. In most cases the algorithms were able to deliver a fall detection decision with at least 100 milliseconds remaining before the impact, which is sufficient to inflate a body airbag.

We report a case of simultaneous bilateral thumb metacarpophalangeal ulnar collateral ligament avulsions resulting from airbag deployment during a motor vehicle crash. Upper-extremity airbag injuries are common, but it is rare to sustain bilateral thumb metacarpophalangeal joint ulnar collateral ligament avulsions. In addition, the location of the avulsions was unusual because they occurred proximally rather than the more common distal ulnar collateral ligament injuries. It is possible that injury caused by airbag deployment favors symmetrical proximal injury of the ulnar collateral ligament. Key words: airbag, thumb metacarpophalangeal joint ulnar collateral ligament

In this paper, the effects of the packaging module housing of MEMS airbag sensor for signal generation is studied. Conventional airbag sensor packaging module for automobiles is composed of the accelerometer MEMS sensor mounted on a printed circuit board, which is assembled inside a plastic housing. And the entire module is mechanically installed by bolts on the automobile frame structure to capture the acceleration from the structure vibration. In this case, the signal path from the frame to the sensor is complex, and the frame vibration is interacted with the module vibration, which may delay and distort the original signal pattern. To remove housing vibration effects, a new sensor packaging on the flexible circuit board was introduced to attach directly on the frame structure surface using adhesive. For the signal characterization, impact tests were performed for the conventional sensor packaging and the directly attached sensor using an aluminum channel and automobile side frame. Numerical analyses were also carried out to understand the vibration effects of the packaging module and the structure. It was found that the vibration behaviors of the frame structure and the module housing, and the module installation location had significant influence on the impact signal generations. The results indicated that the design of the airbag sensor packaging system for proper airbag explosion requires comprehensive engineering considerations.

The use of Pipeline Inspection Gauges (PIGs) to clean the pipes and understand the exact location of existing pipes is essential to protect them from damage during operation. In-depth study of the most important component sealing disc is a new method to solve the failure of the current PIG in the working process. This study focuses on redesigning the sealing disc in combination with soft robot drive technology. First, the structure of a new multi-airbag sealing disc is composed of a conventional sealing disc and a plurality of airbags located above it. Then, the multi-airbag sealing disc was successfully fabricated by using 3D printing technology and multi-step molding, and finally the active control of the multi-airbag sealing disc was realized by inflating the airbag. For the newly designed multi-airbag sealing disc, the most important concern is the bending angle β of the sealing disc and the expansion ratio η of the airbag. Numerical and experimental results were compared to verify the accuracy of the numerical method. Based on this method, the effects of the position of the airbag, the height rate, and the thickness rate on the bending angle of the multi-airbag sealing disc and the expansion ratio of the airbag were studied. The results show that at a given air pressure, the position of the airbag does not substantially affect the expansion ratio of the airbag itself, and the smaller the distance between the airbag and the outer edge of the sealing disc, the easier it is to bend the sealing disc. The larger the height rate, the smaller the thickness rate, and the larger the bending angle of the sealing disc, the larger the expansion ratio of the airbag.

In this study, the dynamic performance of a long curved river-crossing pipeline with multiple floating bodies during immersion process is investigated in detail. Based on the pipeline theory, six degree-of-freedom buoy theory, winch theory, and multi-body coupling theory, a numerical model of the immersion system with multiple floating bodies is established. The numerical calculation method is observed to conform well with the field measurement results. The dynamic performance of the immersion system is comprehensively investigated based on varying key parameters, e.g. the deflation time of the airbags, lowering speed of the suspension cables, and airbag deflation methods. The results from the numerical simulations indicate that the immersion process for the pipeline with the proposed construction method is safe, stable, and controllable. The presented numerical calculations and results can provide valuable construction recommendations to avoid potential engineering risks and ensure the economic efficiency of this or future similar projects.

Tensairity dome is a lightweight spatial structure composed of struts stabilized by cables and airbags inflated by low pressurized air. Two forms of Tensairity domes with annular airbags, stiffened with central cables or webs placed between the upper and lower chords, were proposed based on the Tensairity concept. The zero-stress state, the initial state and the loaded state were successively simulated to investigate the static behavior of the structures, respectively. The results indicate that both two forms of structure have good static performance and the internal pressure in the airbag at about 1000–4000 Pa can ensure the stabilizing role of the inflated airbag. The investigation reveals the subtle interplay between the internal pressure and external loads in the load state, and the tremendous effect of temperature change on overall structure is predicted. The comparisons also show the benefits of webs in the structure for all load cases. Finally, the results show the attractive advantages of Tensairity dome in comparison with conventional structures in terms of structure weight and overall stiffness.

Objective Advanced occupant protection systems in motor-vehicles (e.g., seat belts and airbags), while widely adopted for front-seat passengers, are either absent or offer disproportionally lower safety to rear-seat passengers in similar crashes. Optimization of advanced restraint systems for the rear-seat environment will require a detailed understanding of epidemiology and associated risk factors for injuries sustained by rear-seat passengers. Thus, the objective of the study is to use national level motor-vehicle travel and crash data to quantify rear-seat travel exposure, and determine the descriptive characteristics and the injury outcomes for rear-seat passengers involved in frontal collisions. Methods While U.S. travel data from the 2009 National Household Travel Survey was used to determine rear-seat travel estimates, crash data from 2001 to 2010 National Automotive Sampling System Crash Worthiness Data System was used to enroll rear-seat passengers injured in a frontal crash. The descriptive epidemiology of rear-seat crash victims was separately done for the three age-groups: children (8–15 years old), adults (16–59 years old), and senior adults (60+). Results The study indicated that senior adults in rear-seats were associated with a significantly higher rate of sustaining fatal (6%) and severe injuries (16% for MAIS 3+ injuries) in comparison to the younger cohorts. The distribution of severe injuries further indicated that the thorax was the most frequently injured region across all age groups irrespective of the belt-use status. Conclusions Findings of the study conclude that while rear-seat travel in the U.S. is still very low and improving belt usage is a primary concern among rear-seat passengers; however, the epidemiology supports the need for adapting rear-seat restraint performance for effective protection for all groups of rear-seat passengers.

This paper presents a CMP process analysis considering an airbag type wafer carrier, which is used in semiconductor devices manufacturing. In the CMP process, a wafer is compressed against the polishing pad inside the wafer carrier, which consists of the retainer ring and the membrane film. Structural analysis model is developed to estimate contact pressure distribution over the wafer surface considering the airbag compression behaviour. The polishing experiment without wafer rotation indicated a unique pressure variation around the trailing edge of the wafer. The developed analysis estimated the same phenomena accurately and clarified the mechanism deteriorating the polishing pressure uniformity.

A projector which uses a rotating slide structure to project aperiodic sinusoidal fringe patterns at high frame rates and with high radiant flux is introduced. It is used in an optical three-dimensional (3D) sensor based on coded-light projection, thus allowing the analysis of fast processes. Measurements of an inflating airbag, a rope skipper, and a soccer ball kick at a 3D frame rate of more than 1300 independent point clouds per second are presented.

Inadequate seismic performance of unreinforced masonry (URM) buildings is frequently encountered in earthquake prone countries such as Italy and New Zealand and consequently, effective and economical retrofit strategies need to be adopted in order to guarantee safety and the preservation of the URM building stock. The retrofit technique studied herein consisted of connecting vertical timber elements (strong-backs), to the interior surface of the walls of a building using mechanical screws or bolts. The vertical timber framing is typically a non-structural support for the inner wall lining of URM buildings and its use, as a part of the retrofits, resulted in being a cost effective and low impact solution. The out-of-plane behaviour of as-built and retrofitted masonry walls was investigated by conducting full scale static airbag tests. The walls were subjected to semi-cyclic out-of-plane loading through the application of uniformly distributed loads, using inflated airbags in order to simulate the self-weight inertia force induced by an earthquake. Five different wall specimens were tested in the as-built and retrofitted conditions, the improvement of out-of-plane seismic capacity was recorded and the performances of different retrofit configurations were investigated. A simplified numerical model to predict the response of the masonry wall retrofitted using timber strong-backs was developed using the finite element software SAP2000. Its effectiveness was validated by means of a comparison between the experimental and the numerical results as well as a sensitivity analysis of the model on parameter variations, and further considerations on the retrofit solution were drawn.

The current practice of crash characterization in highway engineering reduces multiple dimensions of crash contributing factors and their relative sequential connections, crash sequences, into broad definitions, resulting in crash categories such as head-on, sideswipe, rear-end, angle, and fixed-object. As a result, crashes that are classified in the same category may contain many different crash sequences. This makes it difficult to develop effective countermeasures because these crash categorizations are based on the outcomes rather than the preceding events. Consequently, the efficacy of a countermeasure designed for a specific type of crash may not be appropriate due to different pre-crash sequences. This research seeks to explore the use of event sequence to characterize crashes. Additionally, this research seeks to identify crash sequences that are likely to result in severe crash outcomes so that researchers can develop effective countermeasures to reduce severe crashes. This study utilizes the sequence of events from roadway departure crashes in the Fatality Analysis Reporting System (FARS), and converts the information to form a new categorization called "crash sequences." The similarity distance between each pair of crash sequences were calculated using the Optimal Matching approach. Cluster analysis was applied to group crash sequences that are etiologically similar in terms of the similarity distance. A hybrid model was constructed to mitigate the potential sample selection bias of FARS data, which is biased toward more severe crashes. The major findings include: (1) in terms of a roadway departure crash, the crash sequences that are most likely to result in high crash severity include a vehicle that first crosses the median or centerline, runs-off-road on the left, and then collides with a roadside fixed-object; (2) seat-belt and airbag usage reduces the probability of dying in a roadway departure crash by 90%; and (3) occupants who are seated on the side of the vehicle that experience a direct impact are 2.6 times more likely to die in a roadway departure crash than those not seated on the same side of the vehicle where the impact occurs.

Neurogenic thoracic outlet syndrome (NTOS) is a disorder that is often misdiagnosed and challenging to treat due to the varied and complex mechanisms that precipitate common sensory symptoms associated with neurovascular dysfunction. In this report, we describe a 21-year-old male who presented with left NTOS after being involved in a motor vehicle collision the previous year. Although NTOS is a condition known to develop after motor vehicle collisions, the mechanism of NTOS in this case, the deploying airbag, has not been documented in existing literature. The patient was first treated conservatively with physical therapy, but treatment failed to relieve his symptoms. A left first rib resection using the transaxillary approach and an anterior scalenectomy was performed without any complications, and the patient's symptoms had improved 3 months postoperation.

Temporal variation has been recognized as one of the major sources of unobserved heterogeneity in traffic safety research that has not been completely addressed. Overlooking temporal variation may result to biased estimates of effects of impact factors. This paper develops a latent class mixed logit model with temporal indicators to investigate highway single-vehicle crashes and the effects of significant contributing factors to driver injury severity. Crash data from 2010 to 2016 in Washington State is collected with a total of 31,115 single-vehicle crashes. The developed model is able to interpret both within- and across- class unobserved heterogeneity and temporal variation. After a careful comparison, a two-class model is selected as the final model. Estimation results show that: two temporal indicators show significant influence on latent class probability functions; urban indicator and principle type are found to be random parameters and have significant heterogeneity in the mean as a function of male indicator and driver’s age indicators. Variables with fixed effects, including animal collision, overturn collision, off-road collision, winter, minor arterial, interstate, wet, snow, ice, speed limit, vehicle age, turning movement, out control movement, lane-change movement, no airbag, deployed airbag, partial and total ejection, seatbelt, and no liability, show significant impacts on different levels of injury severity outcomes in each class. This study provided an insightful understanding of the time-varying effects of the significant factors on driver injury severity using marginal effect analysis, and the temporal indicators in the proposed model were found to enhance the model capability of temporal variation identification.

Background The risk of serious injury or death has been found to be reduced for some front compared to rear seat car passengers in newer vehicles. However, differences in injury severity between car occupants by seating position has not been examined. This study examines the injury severity risk for rear compared to front seat car passengers. Method A retrospective matched-cohort analysis was conducted of vehicle crashes involving injured rear vs front seat car passengers identified in linked police-reported, hospitalisation and emergency department (ED) presentation records during 2001–2011 in New South Wales (NSW), Australia. Odds ratios were estimated using an ordinal logistic mixed model and logistic mixed models. Results There were 5419 front and 4588 rear seat passengers in 3681 vehicles. There was a higher odds of sustaining a higher injury severity as a rear-compared to a front seat car passenger, with a higher odds of rear seat passengers sustaining serious injuries compared to minimal injuries. Where the vehicle occupant was older, travelling in a vehicle manufactured between 1990 and 1996 or after 1997, where the airbag deployed, and where the vehicle was driven where the speed limit was ≥70 km/h there was a higher odds of the rear passenger sustaining a higher injury severity then a front seated occupant. Conclusion Rear seat car passengers are sustaining injuries of a higher severity compared to front seat passengers travelling in the same vehicle, as well as when travelling in newer vehicles and where the front seat occupant is shielded by an airbag deployed in the crash. Rear seat occupant protective mechanisms should be examined. Pre-hospital trauma management policies could influence whether an individual is transported to a hospital ED, thus it would be beneficial to have an objective measure of injury severity routinely available in ED records. Further examination of injury severity between rear and front seat passengers is warranted to examine less severe non-fatal injuries by car seating position and vehicle intrusion.

Ship-launching airbags are widely used in small- and medium-scale Chinese shipyards as a cost-effective substitute for slipways; they are capable of handling launching ship with weights of up to 70,000 tons. However, throughout the 30-year history of these airbags, the safety of the launching process has depended on the high bearing capacity of the airbags and the operators’ experience. Very little theoretical research has been conducted on the ship-launching airbags, and no material constitutive model has yet been established for a ship-launching airbag, especially one that addresses the sandwiched hyperelastic membrane. This study, therefore established a constitutive model for an airbag membrane with reinforcement, through both uniaxial tensile tests and numerical simulations. Isotropic and orthotropic models were developed and compared. The obtained results were found to be in good agreement with the actual test data. Another different size tensile test has also been carried out for eliminating uncertainty of the test. Finally, model-scale data for loaded ship-launching airbags were modeled and computed both theoretically and by Finite Element analysis. The stress and strain results were compared with pressing test data to demonstrate the applicability of the constitutive model to the prediction of safety of using airbags for launching a ship.

We report the case of an 8-month-old baby killed by the deployment of an airbag. He was correctly positioned, in a safety seat designed for his age class, on the passenger side, and rear-facing. The accident occurred at low speed, on the left front of the car, without provoking any harm to the mother who was driving the vehicle, but the impact led to airbag deployment. A CT scan showed an occipital fracture, hemorrhagic parenchymal contusions, subarachnoid hemorrhage and edema, which quickly led to fatal intracranial hypertension. Severe retinal hemorrhages were also noted. Brain death was declared 24h later. Both direct impact and violent projection of the head are involved in the severity of brain lesions. Retinal hemorrhages are similar to what is observed in shaken-baby syndrome. To our knowledge, this is the first French publication on this topic in childhood. In France, children are allowed to be positioned on the passenger side seat, but the airbag, if present, is supposed to be deactivated, which is not always possible. In recent cars, depowering the airbag is easy, with on/off switches, but these systems are not uniform between models. Moreover, it is very likely that this possibility is ignored by numerous parents. A widespread communication on this topic should be initiated in France to prevent such events. Banning infants from front passenger seats completely does not seem possible. Nevertheless, greater attention on the part of police departments and better information to drivers appear necessary. Language: fr

Narrow-track tractors are generally provided with foldable ROPS (roll-over protective structure). Most deaths on narrow tractor rollover occur because of inadequate use of foldable height ROPS. In this research, three automatically deployable ROPS (AD-ROPS) were designed, constructed, and tested to select the best option for installing airbag inflators and deploying time. The best and most reliable option has been found to be SHI2-30V612 inflators in each of the inclined beams of the AD-ROPS. They were tested according to OECD Code 6 Standard and the results obtained were used to assess the ability of the designed AD-ROPS to achieve a positive result in these tests. A 3D graphic computer program was used to predict the test results when mounting the AD-ROPS on a given tractor model and to change these results by varying one or more of the tractor parameters affecting them. For a given tractor model equipped with one of the tested AD-ROPS, it was possible to determine the locus of the AD-ROPS attachment points ensuring both a positive result in the tests and a match to the field of vision requirements. A laboratory-based rollover test of a quad-bike equipped with an AD-ROPS showed that it could effectively protect the driver in the event of a side overturn if the driver remains in his/her seat with the safety belt fastened and with his/her head in a tucked position.

A finite element model of vehicle and its airbag landing attenuation system is established and verified experimentally. Two design cases are selected to constrain the airbag design for extreme landing conditions, while the height and width of airbag and the area of vent hole are chosen as design variables. The optimization is forced to compromise the design variables between the conflicting requirements of the two extremes. In order to optimize the parameters of airbag, the multi-dimensional response surfaces based on extended Latin hypercube design and radial basis function are employed instead of the complex finite element model. Pareto optimal solution sets based on response surfaces are then obtained by multi-objective genetic algorithm. The results show the optimization method presented in this paper is a practical tool for the optimization of airbag landing attenuation system for heavy airdrop.

The installation of airbags as standard equipment in modern cars, combined with the use of seat belts, has reduced the severity of crash-related injuries. However, new airbag-related maxillofacial injuries directly associated with airbag deployment raise questions about the potential dangers of these devices when they operate improperly. Here, we report a rare case of a patient who sustained a mid-facial injury, including a naso-orbital-ethmoid fracture, due to an airbag that inflated improperly when the driver placed her hand on the car's horn switch. The airbag was thought to be deployed following the crash at the same timing of sounding the horn.

The pattern of hand positioning varies considerably as drivers attempt to steer through sharp turns at low speed. The technique chosen by the driver should be the best compromise between car control and driver safety (i.e. airbag deployment). The purpose of this study was to assess different steering techniques in order to characterize the drivers steering profile, defined by tracking hand position. Authors propose a graphical method and a lateral indicator to define driver steering profiles. Tracking of hand steering position in twenty three volunteers with no upper arm disabilities was undertaken with a motion capture system. The steering exercise occurred in a simulator. Results from the hand tracking of steering indicate three distinct driver profiles of: hand-crossing (52%), non-hand-crossing (30%) and asymmetric-hand-crossing (17%). Most subjects steer with one hand and crossed hands often. This present a safety issue for the airbag deploying.

The main cause of death in agriculture has been the overturning of tractors lacking ROPS. Front mounted rollbars are usually foldable to be used in low clearance situations. Most fatal accidents involving tractors with foldable ROPS have occurred because, at the moment of the overturn, the ROPS was at the lower position. In this research, an automatically deployable front-mounted ROPS for narrow tractors, using airbag inflators able to increase simultaneously the height and the upper width of the ROPS, was designed, constructed and tested. The double change of the ROPS geometry reduces the continuous rolling risk, increases the safety zone in a lateral direction, and allows the ROPS height, the bending moments at critical sections and the ROPS beams sections to be reduced. This ROPS has been named ‘Ejectable in Two Dimensions ROPS’ (E2D-ROPS). Using an FE computer program, the necessary sections for E2D-ROPS to be mounted in two tractor models, ensuring a positive result for Code 6 tests, were calculated using different reference masses. An E2D-ROPS prototype was designed, constructed and mounted on a John Deere 60 C tractor. The tractor was tilted and when its lateral inclination reached 60°, an inclinometer activated two airbag inflators, located into its inclined beams, which deployed and locked the E2D-ROPS at its operative position in 102 ms. The E2D-ROPS was tested, using only one airbag inflator located into its transverse beam and was deployed and locked in 312 ms. The system works correctly because these times are lower than the overturn time.

While belt usage among rear-seat passengers is disproportionately lower than their front-seat counterpart, this may have serious consequences in the event of a crash not only for the unbelted rear-seat passenger but also for the front-seat passengers as well. To quantify that effect, the objective of the study is to evaluate the increased likelihood of driver fatality in the presence of unrestrained rear-seat passengers in a severe frontal collision. U.S.-based census data from 2001 to 2009 fatal motor vehicle crashes was used to enroll frontal crashes which involved 1998 or later year vehicle models with belted drivers and at least one adult passenger in the rear left seat behind the driver. Results using multivariate logistic regression analysis indicated that the odds of a belt restrained driver sustaining a fatal injury was 137% (95% CI = 95%, 189%) higher when the passenger behind the driver was unbelted in comparison to a belted case while the effects of driver age, sex, speed limit, vehicle body type, airbag deployment and driver ejection were controlled in the model. The likelihood of driver fatality due to an unrestrained rear left passenger increased further (119–197%) in the presence of additional unrestrained rear seat passengers in the rear middle or right seats. The results from the study highlight the fact that future advances to front row passive safety systems (e.g. multi-stage airbag deployment) must be adapted to take into account the effect of unrestrained rear-seat passengers.

Airbag-based methods for crew impact attenuation have been highlighted as a potential simple, lightweight means of enabling safe land-landings for the Orion Crew Exploration Vehicle, and the next generation of ballistic shaped spacecraft. To investigate the feasibility of this concept during a nominal 7.62 m/s Orion landing, a full-scale personal airbag system 24% lighter than the Orion baseline has been developed, and subjected to 38 drop tests on land. Through this effort, the system has demonstrated the ability to maintain the risk of injury to an occupant during a 7.85 m/s, 0° impact angle land-landing to within the NASA specified limit of 0.5%. In accomplishing this, the personal airbag system concept has been proven to be feasible. Moreover, the obtained test results suggest that by implementing anti-bottoming airbags to prevent direct contact between the system and the landing surface, the system performance during landings with 0° impact angles can be further improved, by at least a factor of two. Additionally, a series of drop tests from the nominal Orion impact angle of 30° indicated that severe injury risk levels would be sustained beyond impact velocities of 5 m/s. This is a result of the differential stroking of the airbags within the system causing a shearing effect between the occupant seat structure and the spacecraft floor, removing significant stroke from the airbags.

This study aims to analyze the effects of environment, vehicle and driver characteristics on the risky driving behavior at work zones. A decision tree is developed using the classification and regression tree (CART) algorithm to graphically display the relationship between the risky driving behavior and its influencing factors. This approach could avoid the inherent problems occurred in the conventional logistic regression models and further improve the model prediction accuracy. Based on the Michigan M-94/I-94/I-94BL/I-94BR highway work zone driving behavior data, the decision tree comprising 33 leaf nodes is built. Bad weather, poor road and light conditions, partial/no access control, no traffic control devices, turning left/right and driving in an old vehicle are found to be associated with the risky driving behavior at work zones. The middle-aged drivers, who are going straight ahead in their vehicles with medium service time and equipped with an airbag system, are more likely to take risky behavior at lower work zone speed limits. Further, the middle-aged male drivers engage in risky driving behavior more frequently than the middle-aged female drivers. The number of lanes exhibits opposing effects on risky behavior under different traveling conditions. More specifically, the risky driving behavior is associated with the single-lane road under bad light or weather conditions while drivers are more likely to engage in risky behavior on the multi-lane road under good light conditions.

Against problems in terms of stability, airtightness and so on of current fast sealing airbag, stability and airtightness of fast sealing airbag in simulating tunnel was studied through combining theoretical analysis and experiment. The ideal viton material is finally found after comparing and analyzing heat resistance, flame resistance, wear resistance, hardness and air permeability of different kinds of rubber. Sealing and wind blocking effects of airbags made from selected material are tested in simulating tunnel. Rate of air leakage and changing rate of wind pressure of each kind of rubber are also determined and further verified, with result that both indexes of viton material are the least, respectively only 4.25% and 4.66%.

An important part of any model of vehicle crashes is the development of a procedure to estimate crash injury severity. After reviewing existing models of crash severity, this paper outlines the development of a modelling approach aimed at measuring the injury severity of people in two-vehicle road crashes. This model can be incorporated into a discrete event traffic simulation model, using simulation model outputs as its input. The model can then serve as an integral part of a simulation model estimating the crash potential of components of the traffic system. The model is developed using Newtonian Mechanics and Generalised Linear Regression. The factors contributing to the speed change (ΔV(s)) of a subject vehicle are identified using the law of conservation of momentum. A Log-Gamma regression model is fitted to measure speed change (ΔV(s)) of the subject vehicle based on the identified crash characteristics. The kinetic energy applied to the subject vehicle is calculated by the model, which in turn uses a Log-Gamma Regression Model to estimate the Injury Severity Score of the crash from the calculated kinetic energy, crash impact type, presence of airbag and/or seat belt and occupant age. Language: en

An airbag is composed of a housing assembly, door assembly, cushion assembly, and an inflator. The inflator is an essential part that generates gas for the airbag. When an airbag is activated, it effectively absorbs the crash energy of the passenger by inflating a cushion. In the present study, tank tests were performed with newly synthesized propellants with various compositions, and the results are compared with the numerical results. In the simulation of the inflator, a zonal model has been adopted which consisted of four zones of flow regions: combustion chamber, filter, gas plenum, and discharge tank. Each zone was described by the conservation equations with specified constitutive relations for gas. The pressure and temperature of each zone of the inflator were calculated and analyzed, and the results were compared with the tank test data. The similarity of the pressure curve and closed bomb calculation show that the modeled results are well correlated with the experimental data.

To overcome the disadvantage of existing fast airtight devices, a latest-model airbag type fast airtight device was devised. Operating principle, structure and installation procedure of the device are presented in detail. Based on related technical parameters of return airway section on working face 15108 of Shi Gang Coal Mine, ANSYS analysis model was created. With a certain pressure and temperature condition, stress and strain in x, y and z directions of the airbag were calculated and the results proved the feasibility of the design proposal. Through field test and analysis of experiment results, the advantage and disadvantage of the latest-model fast airtight device were summarized, in hope to offer some inspiration to the development of airbag type mine airtight device.

One of the critical logic deployment challenges faced by intelligent airbag system is whether the system can accurately determine the type of the occupant sitting in different postures. The main objective of this paper is the application of seat pressure sensors to predict the occupant classification, such as 5th percentile adult female and 50th percentile adult male and 95th percentile adult male. In the experiments, the occupants are recruited to sit in specified postures. During sitting, the pressure data of the occupants are measured. After that, T-S fuzzy model is introduced to investigate the highly nonlinear relationship between the pressure and the weight of the occupant. Finally, the system uses the weight information to determine the type of the occupant. Since the good validity and accuracy of the weight calculated by the T-S fuzzy model are shown in the experiments, the proposed algorithm can effectively identify the type of the occupant.

Statistics show that the landing accounts for the largest portion of all mishaps of unmanned aerial vehicles (UAVs) due to many difficulties including limited situational awareness of the external pilot and the limited maneuverability during the low speed flight before touchdown. In this paper, a vision-based automatic landing system using a dome-shaped airbag is proposed for small UAVs. Its isotropic shape allows airplanes to approach in any direction to avoid crosswind unlike net-assisted landing. The dome’s distinctive color improves the detection owing to its strong visual cue. Color- and shape-based detection vision algorithms are applied for robust detection under varying lighting conditions. Due to the insufficient accuracy of navigation sensors, a direct visual servoing is used for terminal guidance. The proposed algorithm is validated in a series of flight tests.